Radiation imaging apparatus, radiation imaging system, control method, and storage medium

Abstract

Provided is a mechanism for enabling a radiation generation apparatus to accurately perform control processing to stop irradiation of radiation. The mechanism includes a dose calculation unit that calculates a cumulative dose of radiation detected by a sensor unit from start of imaging, a timer unit that measures an irradiation time for radiation from a predetermined timing, a threshold decision unit that sets an irradiation stop threshold based on the irradiation time, a control unit including a threshold determination unit that transmits an irradiation stop signal to stop irradiation of radiation to the radiation generation apparatus when the cumulative dose reaches the irradiation stop threshold, and a sensor unit that detects radiation from the radiation generation apparatus. When the dose calculation unit calculates the cumulative dose having reached a predetermined amount from start of imaging, the threshold determination unit causes the timer unit to start measurement of the irradiation time.

What is claimed is: 
     
         1 . A radiation imaging apparatus comprising:
 a sensor configured to detect radiation from a radiation generation apparatus;   a processor; and   a memory storing a program which, when executed by the processor causes the radiation imaging apparatus to:   transmit a signal for stopping irradiation of radiation to the radiation generation apparatus using a cumulative dose of the radiation detected by the sensor, an irradiation time for the radiation, an irradiation start threshold, and an irradiation stop threshold,   wherein, after the cumulative dose reaches the irradiation start threshold which can be changed by an operator's operation, the signal for stopping irradiation of radiation is transmitted to the radiation generation apparatus based on the irradiation stop threshold obtained by using the irradiation time and the irradiation start threshold.   
     
     
         2 . The radiation imaging apparatus according to  claim 1 , wherein measurement of the irradiation time is started when the cumulative dose reaches the irradiation start threshold. 
     
     
         3 . The radiation imaging apparatus according to  claim 2 , wherein setting of the irradiation stop threshold is controlled based on a target value of the cumulative dose in radiation imaging, the irradiation time, and a delay time from transmission of the signal for stopping irradiation of the radiation to stopping of irradiation of the radiation in the radiation generation apparatus. 
     
     
         4 . The radiation imaging apparatus according to  claim 3 , wherein the processor further causes the radiation imaging apparatus to transmit the signal for stopping irradiation of the radiation to the radiation generation apparatus,
 wherein the delay time is derived based on the communication delay time in communication between the processor and the radiation generation apparatus.   
     
     
         5 . The radiation imaging apparatus according to  claim 4 ,
 wherein the delay time is derived based on the communication delay time in a communication mode for the radiation imaging among a plurality of communication modes.   
     
     
         6 . The radiation imaging apparatus according to  claim 4 , wherein a plurality of the communication delay times is acquired before the radiation imaging is performed. 
     
     
         7 . The radiation imaging apparatus according to  claim 6 , wherein the delay time is derived based on one of the plurality of communication delay times. 
     
     
         8 . The radiation imaging apparatus according to  claim 6 , wherein the delay time is derived based on an average value of some or all of the plurality of communication delay times. 
     
     
         9 . The radiation imaging apparatus according to  claim 6 , wherein the delay time is derived based on a minimum value of the plurality of communication delay times. 
     
     
         10 . The radiation imaging apparatus according to  claim 1 , wherein in a case where no response is received from the radiation generation apparatus for a predetermined period in response to the transmission of the signal for stopping irradiation of the radiation, the signal for stopping irradiation of the radiation is retransmitted to the radiation generation apparatus. 
     
     
         11 . The radiation imaging apparatus according to  claim 1 , wherein a timing of the transmission of the signal for stopping irradiation of the radiation is determined based on the irradiation time and an irradiation start threshold. 
     
     
         12 . A radiation imaging system comprising:
 a radiation imaging apparatus including a sensor configured to detect radiation from a radiation generation apparatus;
 a processor; 
 a memory storing a program which, when executed by the processor causes the radiation imaging apparatus to: 
 transmit a signal for stopping irradiation of radiation to the radiation generation apparatus using a cumulative dose of the radiation detected by the sensor, an irradiation time for the radiation, and an irradiation time for the radiation, an irradiation start threshold, and an irradiation stop threshold, 
 wherein, after the cumulative dose reaches the irradiation start threshold which can be changed by operator's operation, the signal for stopping irradiation of radiation is transmitted to the radiation generation apparatus based on the irradiation stop threshold obtained by using the irradiation time and the irradiation start threshold; and 
   the radiation generation apparatus.   
     
     
         13 . A control method for a radiation imaging apparatus, the control method comprising:
 detecting radiation from a radiation generation apparatus by a sensor;   transmitting a signal for stopping irradiation of radiation to the radiation generation apparatus using a cumulative dose of the radiation detected by the sensor, an irradiation time for the radiation, an irradiation start threshold, and an irradiation stop threshold; and   after the cumulative dose reaches the irradiation start threshold which can be changed by an operator's operation, the signal for stopping irradiation of radiation is transmitted to the radiation generation apparatus based on the irradiation stop threshold obtained by using the irradiation time and the irradiation start threshold.   
     
     
         14 . A storage medium storing a program for causing a computer to execute the control method according to  claim 13 . 
     
     
         15 . The radiation imaging apparatus according to  claim 1 , wherein the irradiation start threshold is the cumulative dose in a stable state of irradiation from the radiation generation apparatus. 
     
     
         16 . The radiation imaging apparatus according to  claim 1 , wherein setting of the irradiation stop threshold is controlled based on a target value of the cumulative dose in radiation imaging, the irradiation time, and a delay time, the delay time corresponding to a time when a tube voltage in a radiation tube has started to drop to a time when the tube voltage has dropped to a minimum voltage level.